1. Field of the Invention
This invention relates to an eyeglass frame comprising members, particularly hinge members, which are connected by a screw joint which is protected from becoming loose.
2. Description of the Prior Art
It is known that this object can be accomplished by plastic elements which control the friction between the parts of the joint. Such means consisting of plastic have been disclosed, e.g., in German patent specification No. 23 56 818 but must be removed when soldering work is to be performed on the eyeglass frame and must subsequently be inserted again. Screws provided with restraining means which consist entirely of metal have already been used and have been described, e.g., in German Utility Model 86 26 588 and Austrian patent specification No. 386,486. But such restraining means are provided with nuts, so that they are bipartite and in accordance with the last-mentioned reference said restraining means comprise a conical member, which is inserted into mating eyelets of the hinge so that inaccurate fits may result in a clamping of the hinge. From German patent specification No. 89 49 18 it is known in small hinges to provide a conical screw head which fits a conical opening in a member of the frame. In that case the resulting joint can be intentionally loosened only with difficulty, particularly if the screw has been firmly tightened, and such tightening and loosening will usually damage the head of the screw adjacent to the groove so that the screw cannot be re-used.